An antimatter explosion threatens to level the Vatican in
the movie adaptation of the thriller "Angels and Demons," but
real-world physicists are unfazed by this plot.

The story features "Da Vinci Code" hero Robert
Langdon racing to recover an antimatter capsule stolen from the CERN particle
physics facility in Switzerland. Researchers first figured out how to create
and trap antimatter particles at CERN, which gave author Dan Brown the
inspiration for his story.

One physicist doesn't find CERN's unexpected publicity from
the story upsetting. On the contrary, he's rather pleased.

"I always say that what Dan Brown did for the Roman
Catholic Church in 'The Da Vinci Code,' he did for me and my research with
'Angels and Demons,'" said Gerald Gabrielse, a Harvard physicist who
currently leads an international research team at CERN.

Antimatter is real, but it still represents a baffling
presence in the universe – sub-atomic particles that are the opposite
of normal matter. When a particle and antiparticle meet, they mutually
annihilate each other and release their entire mass as energy.

This bizarre but intriguing reality has prompted plenty of
science fiction writers to dream of antimatter engines powering future
civilizations or starships, such as Star Trek's U.S.S.
Enterprise.

"Angels and Demons" twists that dream of untapped
energy into more of a nightmarish scenario, by suggesting what might happen if
a relatively large amount of antimatter annihilated itself with matter all at
once. A quarter of a gram of antimatter threatens to unleash the power of 5,000
tons of TNT and destroy everything within a half-mile radius – or so goes the
fictional story.

The reality is that physicists can only wish they had so
much of the stuff.

"If you take all the antimatter produced in the history
of the world and annihilated it all at once, you wouldn't have enough energy to
boil a cup of tea," Gabrielse told LiveScience.

Antimatter represents a rare
entity in a universe dominated by matter, and scientists still struggle to
understand why. What they do know is that creating antimatter requires
tremendous effort, such as using particle accelerators at CERN to smash together particles at nearly the speed of light.

An occasional antimatter particle may arise naturally when a cosmic
ray strikes Earth's upper atmosphere. But collecting man-made antimatter
particles is much more practical for research.

Physicists have only slowed and trapped a small fraction of
all the produced particles, in this case known as antiprotons. They use
antimatter traps somewhat similar in concept to what "Angels and
Demons" describes, with magnetic fields keeping the antimatter particles
in a vacuum away from any matter.

"You need a container with no walls, that's the
idea," Gabrielse noted. His former project, known as TRAP, successfully created and held charged antiprotons for months.

Now physicists face the more daunting challenge of capturing
neutral antihydrogen atoms. The newer international effort, called ATRAP, has
put together an antihydrogen trap and is working on a second.

"We are trying right now to trap neutral antihydrogen
atoms which we have produced, but no one has succeeded in proving that they've
been trapped yet," Gabrielse said.

Such neutral antihydrogen atoms could theoretically be
clumped together, whereas charged antiprotons are repelled by each other.
Whether an antimatter clump would annihilate with all the power of a small nuke
without blowing itself apart remains an open question – and that still assumes
physicists can create and collect anything close to a quarter of a gram of
antimatter.

One part of "Angels and Demons" may have come
true, although unrelated to antimatter. The fictional plot includes retinal
scanners guarding a CERN lab, and the real-life CERN happened to adopt such
eyeball security after the book came out, Gabrielse explained.

So the plot of "Angels and Demons" doesn't quite
annihilate upon contact with reality, but the real-life mystery of
antimatter may still trump fiction.

"Why the universe is made out of more matter than
antimatter? We don't know the answer to that question at all," Gabrielse
said.

Jeremy Hsu

Jeremy has written for publications such as Popular Science, Scientific American Mind and Reader's Digest Asia. He obtained his masters degree in science journalism from New York University, and completed his undergraduate education in the history and sociology of science at the University of Pennsylvania.